Commit Graph

12 Commits

Author SHA1 Message Date
James Y Knight 7c905063c5 Make utils/update_llc_test_checks.py note that the assertions are
autogenerated.

Also update existing test cases which appear to be generated by it and
weren't modified (other than addition of the header) by rerunning it.

llvm-svn: 253917
2015-11-23 21:33:58 +00:00
Simon Pilgrim 96d34d34b0 [X86][SSE] Added extra vector truncation tests
Baseline comparison to D14588

llvm-svn: 253132
2015-11-14 15:23:59 +00:00
Simon Pilgrim 08d823afe4 [X86][SSE] Added extra vector truncation tests.
Including cases for PR14866

llvm-svn: 245274
2015-08-18 08:37:09 +00:00
Simon Pilgrim 268ef6af0b [X86][SSE] Tidied up vector extend/truncation tests. NFCI.
llvm-svn: 241995
2015-07-12 17:40:49 +00:00
Simon Pilgrim 09f3ff9a0a [DAGCombiner] Add support for TRUNCATE + FP_EXTEND vector constant folding
This patch adds supports for the vector constant folding of TRUNCATE and FP_EXTEND instructions and tidies up the SINT_TO_FP and UINT_TO_FP instructions to match.

It also moves the vector constant folding for the FNEG and FABS instructions to use the DAG.getNode() functionality like the other unary instructions.

Differential Revision: http://reviews.llvm.org/D8593

llvm-svn: 233224
2015-03-25 22:30:31 +00:00
Chandler Carruth 5d1a84b7b8 [x86] Delete still more piles of complex code now that we have a good
systematic lowering of v8i16.

This required a slight strategy shift to prefer unpack lowerings in more
places. While this isn't a cut-and-dry win in every case, it is in the
overwhelming majority. There are only a few places where the old
lowering would probably be a touch faster, and then only by a small
margin.

In some cases, this is yet another significant improvement.

llvm-svn: 229859
2015-02-19 15:21:57 +00:00
Chandler Carruth 8817e5e01b [x86] Remove the insanely over-aggressive unpack lowering strategy for
v16i8 shuffles, and replace it with new facilities.

This uses precise patterns to match exact unpacks, and the new
generalized unpack lowering only when we detect a case where we will
have to shuffle both inputs anyways and they terminate in exactly
a blend.

This fixes all of the blend horrors that I uncovered by always lowering
blends through the vector shuffle lowering. It also removes *sooooo*
much of the crazy instruction sequences required for v16i8 lowering
previously. Much cleaner now.

The only "meh" aspect is that we sometimes use pshufb+pshufb+unpck when
it would be marginally nicer to use pshufb+pshufb+por. However, the
difference there is *tiny*. In many cases its a win because we re-use
the pshufb mask. In others, we get to avoid the pshufb entirely. I've
left a FIXME, but I'm dubious we can really do better than this. I'm
actually pretty happy with this lowering now.

For SSE2 this exposes some horrors that were really already there. Those
will have to fixed by changing a different path through the v16i8
lowering.

llvm-svn: 229846
2015-02-19 12:10:37 +00:00
Chandler Carruth 55db07016e [x86] Teach the unpack lowering to try wider element unpacks.
This allows it to match still more places where previously we would have
to fall back on floating point shuffles or other more complex lowering
strategies.

I'm hoping to replace some of the hand-rolled unpack matching with this
routine is it gets more and more clever.

llvm-svn: 229463
2015-02-17 02:12:24 +00:00
Chandler Carruth 87e580a659 [x86] Teach the 128-bit vector shuffle lowering routines to take
advantage of the existence of a reasonable blend instruction.

The 256-bit vector shuffle lowering has leveraged the general technique
of decomposed shuffles and blends for quite some time, but this never
made it back into the 128-bit code, and there are a large number of
patterns where this is substantially better. For example, this removes
almost all domain crossing in vector shuffles that involve some blend
and some permutation with SSE4.1 and later. See the massive reduction
in 'shufps' for integer test cases in this commit.

This isn't perfect yet for a few reasons:

1) The v8i16 shuffle lowering continues to plague me. We don't always
   form an unpack-based blend when that would be better. But the wins
   pretty drastically outstrip the losses here.
2) The v16i8 shuffle lowering is just a disaster here. I never went and
   implemented blend support here for some terrible reason. I'll do
   that next probably. I've not updated it for now.

More variations on this technique are coming as well -- we don't
shuffle-into-unpack or shuffle-into-palignr, both of which would also be
profitable.

Note that some test cases grow significantly in the number of
instructions, but I expect to actually be faster. We use
pshufd+pshufd+blendw instead of a single shufps, but the pshufd's are
very likely to pipeline well (two ports on most modern intel chips) and
the blend is a *very* fast instruction. The domain switch penalty will
essentially always be more than a blend instruction, which is the only
increase in tree height.

llvm-svn: 229350
2015-02-16 01:52:02 +00:00
Chandler Carruth c06b7fbfc3 [x86] Clean up a few test cases with the update script. NFC
llvm-svn: 229349
2015-02-16 01:39:50 +00:00
Simon Pilgrim 2a9a745328 [X86][SSE] Added dual vector truncation tests.
llvm-svn: 228857
2015-02-11 18:14:35 +00:00
Simon Pilgrim a1540c11ec [X86][SSE] Added vector integer truncation tests - based off pr15524
llvm-svn: 225137
2015-01-04 17:52:00 +00:00